markdownlint: add -g option to check_format and fix mdl errors

-g option using only files known to git, that allow us
to avoid errors from submodules

Also add check if mdl is installed, and gracefull info if not.

Signed-off-by: Maciej Wawryk <maciejx.wawryk@intel.com>
Change-Id: Ib6e1920774ffca81e62d9abebc8d8b4548feb519
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/9086
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Monica Kenguva <monica.kenguva@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Pawel Piatek <pawelx.piatek@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

.github/ISSUE_TEMPLATE/bug_report.md

@@ -7,6 +7,8 @@ assignees: ''
 
 ---
 
+# Bug report
+
 <!--- Provide a general summary of the issue in the Title above -->
 
 ## Expected Behavior

.github/ISSUE_TEMPLATE/intermittent_failure.md

@@ -7,6 +7,8 @@ assignees: ''
 
 ---
 
+# CI Intermittent Failure
+
 <!--- Provide a [test_name] where the issue occurred and brief description in the Title above. -->
 <!--- Name of the test can be found by last occurrence of: -->
 <!--- ************************************	-->

scripts/check_format.sh

@@ -587,16 +587,21 @@ function check_json_rpc() {
 function check_markdown_format() {
 	local rc=0
 
-	echo -n "Checking markdown files format..."
-	mdl -s $rootdir/mdl_rules.rb . > mdl.log || true
-	if [ -s mdl.log ]; then
-		echo " Errors in .md files detected:"
-		cat mdl.log
-		rc=1
+	if hash mdl 2> /dev/null; then
+		echo -n "Checking markdown files format..."
+		mdl -g -s $rootdir/mdl_rules.rb . > mdl.log || true
+		if [ -s mdl.log ]; then
+			echo " Errors in .md files detected:"
+			cat mdl.log
+			rc=1
+		else
+			echo " OK"
+		fi
+		rm -f mdl.log
 	else
-		echo " OK"
+		echo "You do not have markdownlint installed so .md files not being checked!"
 	fi
-	rm -f mdl.log
+
 	return $rc
 }